What’s impressive about the Macintosh is that the team delivered a GUI—including significant design refinements from PARC and the Lisa—on top of a $2.5K machine with 128K of RAM.
Nonsense; who ever claimed that? And it’s not a knock on the Mac; if you ever have the opportunity to use an original Lisa and a Mac 128k side by side, you’ll observe that the Mac’s speed and UI improvements are pretty hard not to notice.